In Vitro Analysis of the Anti-influenza Virus Activity of Pomegranate Products and Fulvic Acid

In traditional cuban medicine, pomegranate fruits have been used to treat acidosis, dysentery, microbial infections, diarrhoea, helminthiasis; haemorrhage and respiratory pathologies [Vuorela et al., 2003; Roig, 1974; Jimenez et al., 1979; Seoane, 1984].Pomegranates contain high levels of Polyphenolic compounds, which are largely responsible for the fruit’s antioxidant properties. A number of studies have demonstrated that polyphenolic complexes derived from other plants have antiviral effects, suggesting that antiviral activity may also reside in the polyphenol (PP) fraction of pomegranates.

The decay of organic matter generates an extremely heterogeneous mixture of organic molecules referred to as humic substances. They are sub-classified on the basis of solubility characteristics. The Fulvic Acid (FA) fraction of humic substances includes a variety of low molecular acidic molecules that are soluble in water under all pH conditions. Antiviral activity of fulvic acid containing Secomet V against poxviruses and SARS has been demonstrated [Kotwal et al., 2006].

The current study was undertaken to evaluate the direct anti-influenza virus activity of pomegranate constituents present in Pomegranate Extracts: Pomegranate Juice (PJ) Pomegranate Liquid Extract (POMxl), Pomegranate Polyphenol enriched Powder Extract (POMxp) and Fulvic Acid (FA). Both Pomegranate Extracts and Fulvic Acid had anti-influenza activity. With regard to Pomegranate Extracts, all of the extracts had rapid antiviral activity when combined with influenza virus. The acidity of PJ and POMxl solutions contributed to anti-influenza activity, but this was not a factor with POMxp. Studies using POMxp showed that brief treatment at room temperature with > 200 ìg/ml PPs substantially reduced the infectivity of H1N1, H3N2, and H5N1 influenza viruses. Generally, the loss of infectivity was accompanied by loss of hemagglutinating activity.

Electron microscopic examination of influenza particles neutralized by PP treatment identified a coating of amorphous material and some damage to virion integrity. Reassortant H5N1 viruses derived from avian isolates were less affected by PP treatment, indicating that PP susceptibility is modulated by small changes in surface glycoproteins. Our analysis supports the development of pomegranate-derived PPs as natural, rapidly active, broad-spectrum anti-influenza agents. Our finding demonstrates rapid anti-influenza virus activity in Pomegranate PPs and the Fulvic Acid.